1. Technical Field
The invention relates to a method for manufacturing coated tablets from tablet cores and coating granulate using a press that has at least one compression chamber, preferably with an upper and a lower punch and a feeding device for tablet cores.
2. Description of the Related Art
Methods according to the related art are based as a rule on so-called rotary tablet machines with a high processing speed.
The manufacture of coated tablets has thus far been performed in two steps:
In the first manufacturing step the future cores of the coated tablets are compressed and in the second step the tabletting material for the lower half of the coating is precompressed, the core is placed on the precompressed bed, and is then compressed to form a coated tablet after tabletting material for the upper half of the coating has been added to the die.
The first manufacturing step can be further differentiated into a loading phase in which the tabletting material is added to the die cavity, a compression phase, and an ejection phase in which the finished tablet is removed from the die with the aid of a lower punch.
The second manufacturing step conventionally consists of a first filling phase in which the tabletting material for the lower half of the coated tablet to be produced is loaded into the die, a precompression phase in which the tabletting material that has been added is precompressed slightly so that the core to be added can be placed, a metering phase in which the core is added to the precompressed bed, a second filling phase in which the upper half of the coating is loaded into the die, a compression phase to compress the coated tablet, and an ejection phase that serves to remove the compressed tablet from the die with the aid of the lower punch.